• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1594-1617
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• 2018

In this paper, we consider a spectrum access scenario which consists of two groups of users, namely Primary Users (PUs) and Secondary Users (SUs) in Cooperative Cognitive Radio Networks (CCRNs). SUs cooperatively relay PUs messages based on Amplify-and-Forward (AF) and Decode-and-Forward (DF) cooperative techniques, in exchange for accessing some of the spectrum for their secondary communications. From the literatures, we found that the Conventional Distributed Algorithm (CDA) and Pragmatic Distributed Algorithm (PDA) aim to maximize the PU sum-rate resulting in a lower sum-rate for the SU. In this contribution, we have investigated a suit of distributed matching algorithms. More specifically, we investigated SU-based CDA (CDA-SU) and SU-based PDA (PDA-SU) that maximize the SU sum-rate. We have also proposed the All User-based PDA (PDA-ALL), for maximizing the sum-rates of both PU and SU groups. A comparative study of CDA, PDA, CDA-SU, PDA-SU and PDA-ALL is conducted, and the strength of each scheme is highlighted. Different schemes may be suitable for different applications. All schemes are investigated under the idealistic scenario involving perfect coding and perfect modulation, as well as under practical scenario involving actual coding and actual modulation. Explicitly, our practical scenario considers the adaptive coded modulation based DF schemes for transmission flexibility and efficiency. More specifically, we have considered the Self-Concatenated Convolutional Code (SECCC), which exhibits low complexity, since it invokes only a single encoder and a single decoder. Furthermore, puncturing has been employed for enhancing the bandwidth efficiency of SECCC. As another enhancement, physical layer security has been applied to our system by introducing a unique Advanced Encryption Standard (AES) based puncturing to our SECCC scheme.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.583-585
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• 2005

WebDAV 프로토콜은 웹상의 공동 저작활동을 지원하기 위한 IETF 표준으로써, 원거리에 있는 사용자들 간에 파일을 공동 편집하고 관리할 수 있도록 해주는 HTTP 프로토콜의 확장이다. 이것은 웹상에서 가상의 작업공간을 구성함으로써, 원격 사용자들 간에 새로운 방식으로 공동작업을 가능하게 한다. 무선 네트워크 기술과 무선 장치의 발달로 이동을 하면서 WebDAV 서버에 접속한 후 협업을 수행한다면 유선 환경보다 효율적인 협업을 할 수 있을 것이다. 본 논문에서는 .NET Compact Framework 환경에서 동작하는 PDA WebDAV 클라이언트를 설계하였다. 본 클라이언트는 무선 네트워크를 지원하는 환경에서 PDA를 이용하여 WebDAV 서버와 HTTP 요청을 통하여 서버 자원을 확인할 수 있다. 이러한 PDA WebDAV 클라이언트는 PDA 환경에 맞는 인터페이스를 가져야 하고, 또한 WebDAV 명세를 따라야 한다. PDA WebDAV 클라이언트는 공간의 제약을 받지 않는 PDA를 이용함으로써 자료의 효율적인 공유 및 교환을 통하여 능동적인 협업 환경을 구축 할 수 있다.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.23-27
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• 2006

As a pervasive healthcare application to help medication of elderly patients, the smart compliance monitors have been recently proposed. In this paper, we present a new smart drug/medicine pack (SDP) for ubiquitous medication monitoring, for which the packaging is either paper packet or blister pack. This ubiquitous compliance monitor is composed of several SDPs and a Bluetooth equipped PDA phone. The SDP is a wireless module that monitors the medication consumption unobtrusively by transmitting the sensed data of 'drug removal' events to the medical center and by reminding patients when they take a dose on their mobile phone. The communication between SDP modules and PDA is realized via Bluetooth. The PDA is basically embedded to indicate the medication record and to alert every prescribed medication time during treatment. Experimental results show that the proposed system works exactly when the SDPs are far within about 2 [m] from PDA.

• Journal of the Ergonomics Society of Korea
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• v.22 no.4
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• pp.27-45
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• 2003

PDAs(Personal Digital Assistants), one of the typical mobile devices, are examined in this study to identify the factors affecting their usability. This study focuses on the menu design of PDAs. Three factors including menu extension method, menu structure, and screen orientation were manipulated in a usability experiment. Task completion times, error rates, and degree of subjective satisfaction were measured. Guidelines for designing a PDA menu are proposed based on the experimental results.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.206-208
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• 2004

A new method to control a remote robot with PDA and wireless network is presented. The needs of remote control systems using a home network environments are increased in these days. To solve the shortage of IP address in network, authorized TCP/IP and unauthorized TCP/IP address are used. The unauthorized TCP/IP is obtained by using MAC Address in the system and Network Layer. The model in the system is similar to Sever&Client in structure. Using this system, it is very easy to combine one network device with other network system. A robot system and PDA are used to show the effectiveness of the control system in home network environments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.945-948
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• 2005

Mobile computing devices are becoming increasingly prevalent in a huge range of physical area, offering a considerable market opportunity. The focus of this paper is on the development of a platform of fault diagnosis system integrating with personal digital assistant (PDA). An improvement of induction machine rotor fault diagnosis based on AI algorithms approach is presented. This network system consists of two parts; condition monitoring and fault diagnosis by using Artificial Intelligence algorithm. LabVIEW allows easy interaction between acquisition instrumentation and operators. Also it can easily integrate AI algorithm. This paper presents a development environment fur intelligent application for PDA. The introduced configuration is a LabVIEW application in PDA module toolkit which is LabVIEW software.

• Journal of Sensor Science and Technology
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• v.13 no.6
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• pp.454-461
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• 2004

We have designed a portable electronic nose (e-nose) system using an array of commercial gas sensors and personal digital assistants (PDA) for the recognition and analysis of volatile organic compounds (VOC) in the field. Field screening of pollutants has been a target of instrumental development during the past years. A portable e-nose system was advantageous to localize the special extent of a pollution or to find pollutants source. The employment of PDA improved the user-interface and data transfer by Internet from on-site to remote computer. We adapted the Lavenberg-Marquardt algorithm based on the back-propagation and proposed the method that could predict the concentration levels of VOC gases after classification by separating neural network into two parts.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.792-795
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• 2006

In this paper, we propose a method of vehicle license plate recognition on PDA for illegal parking car regulation. we classified three kinds of vehicle license plates being used down to date since the introduction of each vehicle license Plate using features of each one. And we recognized vehicle license plates segmentation the AreaName, the AreaCode, the TypeCharacter and the Numbers. A 88.7% recognition accuracy was obtained through the experiment of the proposed vehicle license plate recognition system using the obtained images of PDA.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2692-2695
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• 2008

Polydiacetylene (PDA) is chemosensor materials that exhibit non-fluorescent-to-fluorescent transition as well as blue-to-red visible color change upon chemical or thermal stress. They have been studied in forms of film or microarray chip, so far. In this paper, we provide a novel technique to fabricate continuous micro-fiber PDA sensor using in-situ laser-polymerization technique and 3-D hydrodynamic focusing on a microfluidic chip. The flow of a monomer solution with diacetylene (DA) monomer is focused by a sheath flow on a 3-D microfluidic chip. The focused flow is exposed to 365 nm UV laser beam for in-situ polymerization which generates a continuous fiber containing DA monomers. Then, the fiber is exposed to 254 nm UV light to polymerize DA monomers to PDA. Preliminary results indicate that the fiber size can be controlled by the flow rates of the monomer solution and sheath flows and that a PDA sensor fiber successively responds to chemical and thermal stress.

• Clinical and Experimental Pediatrics
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• v.46 no.11
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• pp.1080-1084
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• 2003

Purpose : To compare perinatal characteristics, clinical courses, and overall morbidity between respiratory distress syndrome(RDS) with patent ductus arteriosus(PDA) and RDS without PDA in neonates. Methods : Eighty-three neonates who were diagnosed and treated for RDS in the neonatal intensive care unit(NICU) from Jan. 2000 to Dec. 2002 were included in this study. RDS was complicated with PDA(group A) in 17 patients and not complicated in 66(group B). PDA was diagnosed by echocardiogram in neonates with congestive heart failure symptom, cardiac murmur or chest X-ray findings of cardiomegaly or pulmonary edema. A retrospective study was undertaken of the perinatal characteristics and overall morbidity in group A and group B. Results : The birth weight and gestational periods of group A were less compared with group B. There was more perinatal asphyxia in group A. Incidence of overall morbidity such as bronchopulmonary dysplasia, intraventricular hemorrhage and death was higher in group A. Intravenous indomethacin was administered in 17 PDA infants. Conclusion : The perinatal characteristics in the two groups showed a significant difference. Incidence of overall morbidity in the two groups showed significant differences, however, there is no simple conclusion to draw because we didn't do multifactorial analyses to rule out other many risk factors affecting morbidity, such as gestational weeks or birth weight.